Journal of Optics TUTORIAL Phase matching in β-barium borate crystals for spontaneous parametric down-conversion To cite this article: Suman Karan et al 2020 J. Opt. 22 083501 View the article online for updates and enhancements. This content was downloaded from IP address 14.139.38.209 on 01/07/2020 at 03:25 Journal of Optics J. Opt. 22 (2020) 083501 (20pp) https://doi.org/10.1088/2040-8986/ab89e4 Tutorial Phase matching in β-barium borate crystals for spontaneous parametric down-conversion Suman Karan1, Shaurya Aarav1,4, Homanga Bharadhwaj2,5, Lavanya Taneja1,6, Arinjoy De3,7, Girish Kulkarni1,8, Nilakantha Meher1 and Anand K Jha1 1 Department of Physics, Indian Institute of Technology Kanpur, Kanpur UP 208016, India 2 Department of Computer Science and Engg., IIT Kanpur, Kanpur UP 208016, India 3 Department of Physics, IIT Kharagpur, Kharagpur 721302, India E-mail:
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[email protected] Received 10 March 2020 Accepted for publication 16 April 2020 Published 29 June 2020 Abstract Spontaneous parametric down-conversion (SPDC) is the most widely used process for generating photon pairs entangled in various degrees of freedom such as polarization, time-energy, position-transverse momentum, and angle-orbital angular momentum (OAM). In SPDC, a pump photon interacts with a non-linear optical crystal and splits into two entangled photons called the signal and the idler photons. The SPDC process has been studied extensively in the last few decades for various pump and crystal configurations, and the entangled photon pairs produced by SPDC have been used in numerous experimental studies on quantum entanglement and entanglement-based real-world quantum-information applications.